Flexible stay-bolt.



B. E. D. STAFFORD. FLEXIBLE STAY BOLT.

APPLICATION FILED HAY 18, 1905.

PATBNTED FEB. 19, 1907.

VPATENT OFFICE.

FLEXIBLE STAY-BOLT.

Specification of Letters Patent.

Patented Feb. 19. 1907.

Application filed May 16.1905. Serial No. 260,713Y

To rt/Z whom t may concern:

Be it known that l, BENJAMIN IC. l). STAFFORD, ot' Pitts burg, in th e county ol" Alle gheny end State of Pennsylvania, have invented certain new und useful improvements in Flexible Stay-Bolts; und l do hereby declare the 'following to be o( lull, clear, ond exiict description of the invention, such as will enable others skilled in the ort to which it cppertoins to molte und use the same.

My invention relatos to on improvement in iiexible stoy-bolts for boilers, the object being to provide a stoy-bolt that con be inserted from the outside and when in place will form absolutely tight joints, thus re venting,I any leakage, ond which will be f ush or procticolly llusli with tho outer foce of the lioiler-sheet or other port, thus permitting it to be used in positions where boils with heads mounted in u. bushing; or )lug which project beyond the sheet cannot lie used With these ends in view my invention consists in the ports ond coinlfiinotions oi ports, als will be more full)v described, and pointed out in the claim.

In the accompanying drawings, .Figure l is a view partly in section, illustratingr my improvement in connection with the inner and outer sheets oii' the boiler, Fig. 2 is :in end view ol the bolt-heini; ond Fig. 3 :in elevation, partly in sectionI of the threaded bushing.

In constructing it stoy-bolt in accord-once with myinvcntion lprovido it bol t l, having o substantially spherical head :Z et one end und a threaded portion :it the other end, the head 2 beingr provided with o slot 3 for the epgogenient of si suitable driver.

Secured within the ou ter shell of the boiler is the bushing 4. This bushing isy made slightly' tapering and is screw-threaded tcrnnllv, so that os it is screwed into the outer plate or shell the wedging,Y produces an obsolutel)Y tight joint. The inner end oi this bushing has un openingr of greater diameter than the diameter ol the body of the holt i and is slightly lhiring, so as to permit of o free lateral movement of the bolts within reasonable limits. This bushing is designed to rcceive the head 2 of the bolt 1 und is provided internally near its inner end with e.

scat 5, formed, preferably, in the orc of a circle for the sphericel head 2 of the bolt 1` thus permitting of movement of the head on the sont during' the exintnsion ond contraction of the plotes to which the bolts are connected.

The portion of thc cavity occu iiod by the hood of the bolt l is plain, While the outer ond ol' the bushing is provided with internal threads to engage the threads on the screwoop (i, 'which latter is designed to close the outer end of thc bushing. This oop 6 when sented in the bushing rests against the annuliir shoulder which hitter limits tho inward penetration oli the cop und prevents the littter from beiner screwed into contoct with the heed. The inner foce of the cop 6 is, however, inode lished or concovcd, as et S, so as to provide :imple clearance-space for the heed oll the bolt and peri'nit of its lree unrestricted pivotal movenients during the lateral movements ol the bolt due to the expansion and contraction ot the shoots to which the bolts tire applied.

With nl v improvement the bushing con be screwed iu linsh with the outer luce of the outer sheet or pluto of lhn boiler, und thus permit of its uso in plone 1where it projectingr )ushine could not he used: Again, the bushing constructed ond secured in place, combined with the spherical hond of the holt., ond the screw-ccp fitting within the bushing ond resting on on annular scat form, when properi)r scoured in place, o water and steam tight joint, sind h v shaping the bolt-head, bushing, oud cop :is above explained the bolt is free to move pivotelly on its heed to compensate for any and fdl variations in the relative positions oi the` ports connected b v snid bolts due to unequal expansion und contraction ot' seid ports.

- In applying my bolt the bushingr is lirst inserted in thc outer sheets and screwed home or until its outer face is approximately vflush with the outer foco of the sheet. TheI holt is then passed through the bushing,r und screwed into the inner sheet or plete until the head of the bolt beurs solidly on its seat in the bushing, after which the bushing is closed by the cop.

It is evident that many slight changes might he resorted to in the relative arrangement ol" parts herein shown and described Without departing; trom the spirit and scope of my invention. Hence l would have it understood that l do not wish to confine inyself to the exact construction herein shown ond described; but,

Having fully described in v invention, what IOO fl claim as newr`ld desire toSeQHI@ by heb ters Patent', is-- A stay-bolt structure (nomprisng in boil` having a head which is sulistantinliy spleen icail'in form, for the passage of the bolt und a` ourvvd sont for that portion. of Lhe spherical hond adjacent to the body of tlm` bolt, said bushing having an enlarged opening in its upper portion terminating in :in annular shouhlnr, hc wall-of sniidioponing being threaded, sind i cap'somwf -into said enlmgedfopmiing und Ming against said ammini' shoulder, the

inner face of said @up boing curved substan- Liully concentric to und l outw- Sphriua] portion of Athehoad and the i outer 0nd oi' said. cap adapted t0 liv` flush with a bushing;r having un owning spaced from the l5 1e outer ond of thc bushing. In testimony whereof I have signed this slwciliuution in tho presence: of twmsubscrib- Izo lng witnesses.

.BENJAMIN E. I). S'I`.-M `I `ORI). Witnesses:

A; WV. BRIGHT, S. G. NOTTINGHAM. 

